Fuller figured and plus size women generally have larger breasts that need to be supported. Thus brassieres for fuller figured and plus size women tend to be underwired in order to provide the required level of support for the larger breasts.
The problem is that as the size of the breast increases the length of the wire used in the underwire also increases. The wire of an underwired bra can thus end up being quite long in brassieres for fuller figured and plus size women. This often results in the underwire digging in to the body under the arms, or the bust of fuller figured and plus size women.
This problem is much worse in plus size women as the brassiere, being tight around the body to provide support, results in flesh being squeezed under the arms and overhang of this flesh above the brassiere results. Furthermore the underwire readily digs into this overhang of flesh resulting in a very painful experience as well as the unsightly overhang of flesh.
In some instances, although it should not normally happen, a smaller wire may have mistakenly been inserted into the underwire channel of a brassiere to eliminate the wire digging into the overhang of flesh, however, the overhang of flesh is still present, and the wire instead digs into the ribcage of the wearer which is equally as painful and can result in bruising. Furthermore the excess fabric of the bra can cause rubbing. One of the biggest problems is due to the machinist pulling on the fabric too much whilst sewing the garment together. When this occurs the channel becomes larger than the wire inserted into the channel. This difference in length between the channel and the wire is called wire play. Whilst some wire play is desired, typically between about 0.5 cm and 1.5 cm, to allow for shrinkage of the material through repeated washing, more wire play than this is undesirable as no support is provided for the wire and such that the wire digs into the flesh of the wearer at the same time as the excess rubs the flesh of the wearer.
The wearing of such uncomfortable brassieres can result in significant health problems such as mastalagia, maceration, intertrigo, bruising, vitiligo and fungal infections.